The combustion pressure of the tanked gas is different from that of the natural gas. A valve set for transferring the tanked gas to a burner is different from a valve set for transferring the natural gas to a burner. If buying a wrong valve, a user will have to ask for refund or replacement. Such refund or replacement is troublesome.
Generally, people use the tanked gas outdoors. Hence, an outdoor burner is generally equipped with a valve set adapted to transfer the tanked gas. On the other hand, there are outdoor sites such as market places where the natural gas is provided. In these sites, users prefer the natural gas to the tanked gas. For a user who has to move from one place to another very often, it would be better for him or her to bring two valve sets to ensure the proper operation of a burner. If forgetting to bring a valve for the natural gas, it would be troublesome to get one since the valves for the natural gas are sold only in a few places.
Therefore, the present invention is intended to obviate or at least alleviate the problems encountered in prior art.